1. Field of the Invention
The present invention relates to copoly(aromatic sulfone carbonate-aromatic alkylcarbonate)-polysiloxane block copolymer, and more particularly relates to copoly(aromatic sulfone carbonate-aromatic alkylcarbonate)-polysiloxane block copolymer having high glass transition temperatures.
2. Description of Related Art
Organopolysiloxane-polycarbonate block copolymers are well known in the art. See, for example, U.S. Pat. Nos. 3,189,662; 4,027,072; and 4,123,588; all of which are incorporated herein by reference. While these copolymers are useful as flexible thermoplastics, thermoplastic elastomers and adhesive layers for laminates, they have lower glass transition temperatures than are desired for some applications.
Polyarylsulfone carbonates derived from bis-(3,5-dimethyl-4-hydroxyphenylsulfone), 2,2-bis(4-hydroxyphenylpropane) and phosgene are also known but they are generally too brittle to be employed in applications requiring flexibility and a degree of elasticity.
Accordingly, one object of the present invention is to provide copolymers having the combined properties of suitably high glass transition temperatures and flexibility.